Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine (Guangdong Provincial Hospital of Chinese Medicine), Guangzhou, China; State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.
Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine (Guangdong Provincial Hospital of Chinese Medicine), Guangzhou, China; Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China.
J Pharm Biomed Anal. 2024 Nov 15;250:116396. doi: 10.1016/j.jpba.2024.116396. Epub 2024 Aug 8.
Critical events in Alzheimer's disease (AD) involve an imbalance between the production and clearance of amyloid-β (Aβ) peptides from the brain. The ratio of Aβ42 to Aβ40 in plasma was useful for evaluating AD, but quantification is limited by factors including preanalytical analyte loss and insufficient sensitivity. The availability of a targeted UPLC-MS/MS method with adequate analytical sensitivity and accurate values traceable to the SI units is essential for implementing a strategy for assay standardization. A targeted UPLC-MS/MS method for plasma Aβ42 and Aβ40 quantification was developed based on selected characteristic peptides spiked by N-labeled Aβ. The calibrator was assigned using an amino acid analysis reference method trace to SI units. UPLC-MS/MS conditions and sample preparation procedures were assessed. 59 plasma samples comparison were used to evaluate immunoassays. Additionally, two clinical cohorts were selected for diagnostic performance evaluation. The LOQ of Aβ42 and Aβ40 is 10 pg mL and 20 pg mL, respectively. The linear range was 10-500 pg mL for Aβ42 and 20-1000 pg mL for Aβ40, recoveries between 95.3 % and 108.2 % for Aβ42, 93.2 % and 104.1 % for Aβ40, imprecisions were <7 %. The accuracy of method was validated by analysis of a certified reference material. Clinical cohorts for diagnostic performance evaluation shown that the area under the curve (AUC) for plasma Aβ42 and Aβ42/Aβ40 to differentiate between AD and CN were 0.767 and 0.799, respectively. A robust UPLC-MS/MS method was developed and demonstrated that suitable for a wide range of plasma Aβ42 and Aβ40. Applied to the investigation of clinically discrepant results, this method can act as an arbiter of the concentration of plasma Aβ42 and Aβ40 present.
阿尔茨海默病（AD）的关键事件涉及大脑中淀粉样β（Aβ）肽的产生和清除之间的失衡。血浆中 Aβ42 与 Aβ40 的比值可用于评估 AD，但定量分析受到包括分析物在预处理过程中的损失和灵敏度不足等因素的限制。建立一种具有足够分析灵敏度和可溯源至 SI 单位的准确值的靶向 UPLC-MS/MS 方法，对于实施分析标准化策略至关重要。基于 N 标记的 Aβ 标记的特征肽，建立了一种用于定量检测血浆 Aβ42 和 Aβ40 的靶向 UPLC-MS/MS 方法。采用氨基酸分析参考方法，溯源至 SI 单位，对校准品进行赋值。评估了 UPLC-MS/MS 条件和样品制备程序。使用 59 份血浆样本比较来评估免疫测定法。此外，还选择了两个临床队列进行诊断性能评估。Aβ42 和 Aβ40 的 LOQ 分别为 10 pg mL 和 20 pg mL。Aβ42 的线性范围为 10-500 pg mL，Aβ40 的线性范围为 20-1000 pg mL，Aβ42 的回收率为 95.3%-108.2%，Aβ40 的回收率为 93.2%-104.1%，精密度<7%。通过对认证参考物质的分析验证了方法的准确性。用于诊断性能评估的临床队列表明，区分 AD 和 CN 的血浆 Aβ42 和 Aβ42/Aβ40 的曲线下面积（AUC）分别为 0.767 和 0.799。建立了一种稳健的 UPLC-MS/MS 方法，该方法适用于广泛的血浆 Aβ42 和 Aβ40 范围。应用于对临床结果不一致的研究，该方法可以作为判断血浆 Aβ42 和 Aβ40 浓度的仲裁者。
